A variety of packers are used in wellbores to isolate specific wellbore regions. A packer is delivered downhole on a conveyance and expanded against the surrounding wellbore wall to isolate a region of the wellbore. Often, two or more packers can be used to isolate one or more regions in a variety of well related applications, including production applications, service applications and testing applications.
In some applications, packers are used to isolate regions for collection of formation fluids. For example, a straddle packer can be used to isolate a specific region of the wellbore to allow collection of fluids. A straddle packer uses a dual packer configuration in which fluids are collected between two separate packers. The dual packer configuration, however, is susceptible to mechanical stresses which limit the expansion ratio and the drawdown pressure differential that can be employed.
An addition problem with inflatable packers in general, is that they are typically cured in an air autoclave. Prior to curing, a polyamide bandage is typically wrapped around the inflatable packer at a given tension, to apply a pressure on the outside diameter of the inflatable packer. This polyamide bandage is then removed after curing. This process has several weaknesses. For example, the polyamide bandage doesn't seal the inflatable packer against exposure to air. As such, the rubber of the inflatable packer is exposed to high pressure air in the autoclave. This introduction of air into the rubber can significantly reduce the quality of the rubber due to oxidation. In addition, this air can migrate through the rubber, creating some high pressure bubbles. These bubbles can “explode” when the air pressure is released, greatly reducing the quality of the rubber. Also, the polyamide bandage itself is exposed to pressurized air in the autoclave, risking oxidation to the polyamide bandage and resulting property losses in the polyamide bandage. As such, a need for a new inflatable packer curing process exists.